Empowering yourself doing it is worth the trouble. I still remember the first day I mixed a raw formula. It was Dudley's. Just an amazing feeling to realize that you really can do this. At that time, I mixed in an open barrel with my hands.

Empowering yourself doing it is worth the trouble. I still remember the first day I mixed a raw formula. It was Dudley's. Just an amazing feeling to realize that you really can do this. At that time, I mixed in an open barrel with my hands.

It's really a great way to start. You can buy 20lbs of the materials at any pottery. You need a decent scale and a bucket. Mixing with your hands really does work, not as well as a mixer but it works. It just lets you know you can make your own glass.

To me, that's empowering.

You need Silica, soda ash, Potassium carb, calcium carb ,sodium nitrate and some antimony oxide. The antimony may not come from a pottery but Universal pigment certainly has it. Mix a formula, throw it in a pot that's at least 2200F, let it melt and go flat, add more, wash rinse repeat. It takes about 8 hours after the last charge. Keep it at least 2200F. You'll have glass the next day. Add metallic oxides for color at about .1 percent max.

Henry Summa initially used something much like that in the early days when he was in New York. Cheap, fairly effective, takes up no space. Our little 7 inch crucibles don't cost much and if you prefer, Assay pots cost even less. My first pot furnace was built in a 55 gallon drum sawed off with a kast-o-lite 30 lid. Really low tech.

As to the mixer, the proof is in the pudding. It melts or it doesn't or something in between but the glass is talking to you. If you consider the cost of color rods compared to the cost of DYI , you'll be floored. Further, you'll make glass that doesn't look like everyone else's. The copper blue I'm using right now is absolutely electric and incredibly simple.

Read the stuff I wrote in Glassnotes IV on batching. It's a simply guide to doing it.

I am working with Spruce Pine Batch W/er87. Melting in an electric furnace with 50 lbs test melts at 2350 for about 4 hour melt, drop to 1900 for 4 hour soak and back up to working at 2130. That can be adjusted I think.

First tow melts with STPP Molecular FormulaNa5O10P3 Did not have any visible opalescence. My third test worked but was not an ideal system.

50 lbs SP batch
907 g STPP

Image #1 Full reheat - After a started Bubble is allowed to cool, the second gather and a full reheat caused the density to develop.

Image #2 Fresh gather cast and pressed. no reheat

Image #3 Spot heat with hot torch. My favorite so far

Image #4 started bubble allowed to cool and gathered with a limited reheat

Image #5 Spot heating with Torch on cast glass.

Amazing the variation heat has on this glass.

Does anyone have recommendations on getting the phosphate to strike on the cool down vs the reheat? I want to use this is casting /press molding but I do not have the option of reheating my castings without loosing the shape and texture. See image 5 for best results.

What Mark did in the "Ladder to the moon group was to cast the basic phosphate material and then press a "ladder into that mold. That caused a chill. Then the casting continued and the interface was opalescent.

If it's not encased, that is some really smooth looking opal phos. Nice job!

However, if it is, that much STPP (2lbs in 50lbs) is going to escalate your expansion beyond compatibility...I'm estimating a shift from 96 to over 100. No biggie, add sand if you foresee using this with another blowing glass.

I just made some more 3.2% using Dave's formula. This is striking on cool down...actually pretty dense from the pot. Your percentage is pretty close to this...maybe push it to 4 or 5% range like Jordan. Good texture (see pic) but your SP mod looks pretty damn good...especially with a fast and furious melt schedule. Left to right: encased in clear, clear encased in bross, all-bross. So far compatible but we'll see.

I just got some SP87w/ Er "snowflake" and gonna try your method. Thanks for trying something new and sharing your results!

All published comments within these message boards are the opinions of its contributor and does not represent
the opinion(s) of the owner(s) of this website. Please see the Terms of Use file for more details.